SELECT 
  1 
FROM 
  cscart_june_setupec_print_temp_designs 
WHERE 
  session_id = 'U97T-RLJ4-RGQR-7VST-5Q3V-RQ9E-5ADS-18E0' 
  AND product_id = 164 
  AND expires_at > 1781895678 
  AND confirmed = 'Y' 
LIMIT 
  1

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}